| Message ID | 1308251204-16719-2-git-send-email-marc.zyngier@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thursday 16 June 2011, Marc Zyngier wrote: > @@ -147,6 +148,19 @@ static int __init timer_init_syscore_ops(void) > > device_initcall(timer_init_syscore_ops); > > +void (* __initdata arm_late_time_init)(void); > + > +static void __init __arm_late_time_init(void) > +{ > + if (arm_late_time_init) > + arm_late_time_init(); > + > +#ifdef CONFIG_LOCAL_TIMER_DEVICES > + early_platform_driver_register_all("localtimer"); > + early_platform_driver_probe("localtimer", 1, 0); > +#endif > +} > + > void __init time_init(void) > { > system_timer = machine_desc->timer; Instead of having two separate global pointers, should we make the ARM specific callback a machine_desc callback? Arnd
On 17/06/11 15:56, Arnd Bergmann wrote: > On Thursday 16 June 2011, Marc Zyngier wrote: >> @@ -147,6 +148,19 @@ static int __init timer_init_syscore_ops(void) >> >> device_initcall(timer_init_syscore_ops); >> >> +void (* __initdata arm_late_time_init)(void); >> + >> +static void __init __arm_late_time_init(void) >> +{ >> + if (arm_late_time_init) >> + arm_late_time_init(); >> + >> +#ifdef CONFIG_LOCAL_TIMER_DEVICES >> + early_platform_driver_register_all("localtimer"); >> + early_platform_driver_probe("localtimer", 1, 0); >> +#endif >> +} >> + >> void __init time_init(void) >> { >> system_timer = machine_desc->timer; > > Instead of having two separate global pointers, should we make the ARM specific > callback a machine_desc callback? Probably not. I only see this arm_late_time_init pointer as a temporary measure. The only user (shmobile) uses this hook to install its own early timers, and there is a patch floating around to move that code to time.c. Unless we have other uses for such a callback, of course. M.
On Friday 17 June 2011, Marc Zyngier wrote: > > > > Instead of having two separate global pointers, should we make the ARM specific > > callback a machine_desc callback? > > Probably not. I only see this arm_late_time_init pointer as a temporary > measure. The only user (shmobile) uses this hook to install its own > early timers, and there is a patch floating around to move that code to > time.c. Unless we have other uses for such a callback, of course. Ok, fair enough. Arnd
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index cdc89ed..dafb20a 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1415,7 +1415,7 @@ config HOTPLUG_CPU config LOCAL_TIMERS bool "Use local timer interrupts" - depends on SMP + depends on SMP && !LOCAL_TIMER_DEVICES default y select HAVE_ARM_TWD if (!ARCH_MSM_SCORPIONMP && !EXYNOS4_MCT) help @@ -1424,6 +1424,9 @@ config LOCAL_TIMERS accounting to be spread across the timer interval, preventing a "thundering herd" at every timer tick. +config LOCAL_TIMER_DEVICES + bool + source kernel/Kconfig.preempt config HZ diff --git a/arch/arm/include/asm/mach/time.h b/arch/arm/include/asm/mach/time.h index d5adaae..f46ca39 100644 --- a/arch/arm/include/asm/mach/time.h +++ b/arch/arm/include/asm/mach/time.h @@ -43,5 +43,6 @@ struct sys_timer { }; extern void timer_tick(void); +extern void (* __initdata arm_late_time_init)(void); #endif diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c index cb634c3..32d0df8 100644 --- a/arch/arm/kernel/time.c +++ b/arch/arm/kernel/time.c @@ -24,6 +24,7 @@ #include <linux/syscore_ops.h> #include <linux/timer.h> #include <linux/irq.h> +#include <linux/platform_device.h> #include <linux/mc146818rtc.h> @@ -147,6 +148,19 @@ static int __init timer_init_syscore_ops(void) device_initcall(timer_init_syscore_ops); +void (* __initdata arm_late_time_init)(void); + +static void __init __arm_late_time_init(void) +{ + if (arm_late_time_init) + arm_late_time_init(); + +#ifdef CONFIG_LOCAL_TIMER_DEVICES + early_platform_driver_register_all("localtimer"); + early_platform_driver_probe("localtimer", 1, 0); +#endif +} + void __init time_init(void) { system_timer = machine_desc->timer; @@ -154,5 +168,6 @@ void __init time_init(void) #ifdef CONFIG_HAVE_SCHED_CLOCK sched_clock_postinit(); #endif + late_time_init = __arm_late_time_init; } diff --git a/arch/arm/mach-shmobile/timer.c b/arch/arm/mach-shmobile/timer.c index 895794b..835baa4 100644 --- a/arch/arm/mach-shmobile/timer.c +++ b/arch/arm/mach-shmobile/timer.c @@ -38,7 +38,7 @@ static void __init shmobile_late_time_init(void) static void __init shmobile_timer_init(void) { - late_time_init = shmobile_late_time_init; + arm_late_time_init = shmobile_late_time_init; } struct sys_timer shmobile_timer = {
Introduce hooks to probe local timers registered as early devices. Use the late_time_init hook to perform the probing. Since shmobile is already using this hook, add an ARM specific arm_late_time_init hook that platforms can use instead. This is controlled by a new config option (LOCAL_TIMER_DEVICES) which prevents LOCAL_TIMERS from being selected, as the two clearly conflict. Cc: Paul Mundt <lethal@linux-sh.org> Cc: Magnus Damm <magnus.damm@gmail.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> --- arch/arm/Kconfig | 5 ++++- arch/arm/include/asm/mach/time.h | 1 + arch/arm/kernel/time.c | 15 +++++++++++++++ arch/arm/mach-shmobile/timer.c | 2 +- 4 files changed, 21 insertions(+), 2 deletions(-)